Process of making wool-like cellulosic textile materials



Pat ent ed Sept. 11 1962 3,053,607 PROCESS OF MAKENG WOOL-LIKECELLULGSKC TEXTILE MATERIALS Hugh C. Gulledge, Newark, Del., assignor toE. I. du Pont de Nernours and Company, Wihnington, Del, a corporation ofDelaware No Drawing. Filed June 2, 1958, Ser. No. 738,925 8 Claims. (Cl.8--117) This invention relates to the production of improved cellulosictextile materials, and more particularly to novel methods for obtainingsuch materials.

This application is a continuation in part of my copending applicationSerial No. 512,307, filed May 31, 1955 (now abandoned).

In my copending US. application Serial No. 707,870, filed January 9,1958 (now US. Patent No. 2,980,490, dated April 18, 1961), novelcellulose products exhibiting improved flame resistance, mildewresistance, and woollike resistance to wrinkling are prepared bysubjecting relatively cheap cotton fabric materials to swelling andmetallation treatments. Briefly, a fibrous textile material, includingcotton, linen, rayon, etc., is subjected to swelling and complexing in asuitable liquid medium containing a swelling agent such as a primary orsecondary amine, the swollen material is then separated from the majorportion of the first amine solution and is then treated with a suitableorganic ester of a metal such as tetraisopropyl titanate. The cellulosematerial at this point of the process is in very highly tenderized,swollen state. When this ester-amine containing cellulose is immersed inwater, it regenerates into its original, strong form and results in theimproved product containing up to 20-25% of the metal oxide or oxides ofthe metallating agent or mixtures of such agents. Following themetallation, excess reagents are removed from the product by a washingtreatment with an anhydrous solvent, such as an alcohol or hydrocarbon.This prevents hydrolysis of the excess metal ester present andproduction of an undesirable dusty product as well as reagent loss. Inthe washing and treating steps, anhydrous solvents employed must beprotected from moisture and to secure an economically attractiveoperation must be recovered. In addition, a 100% utilization andcomplete reaction of the metal ester with the cellulose is not realized.

It has now been found that a desired, more complete 100% utilization ofsuch metal ester can be readily achieved in such process and thatsimplification of handling and recovery of solvents and other liquidsemployed in the metallation can be effected. It is accordingly an objectof this invention to provide novel methods for attaining these resultsas well as for overcoming the existing disadvantages in priormetallation procedures. It is among the specific objects of thisinvention to provide an improved method enabling one to achieve asubstantially 100% metal ester reaction and utilization in suchmetallation process. Other objects and advantages of the invention willbe evident from the ensuing description.

These and other objects are attained in this invention which comprisestreating a cellulosic material with a volatile, anhydrous, liquid,organic primary or secondary amine together with a metallating estercompound, such as an alkyl metallate of a metal having a valence of notless than 3 nor more than 4, evaporating said amine from the wetted,swollen, amine-complexed, tenderized cellulosic material containing theadded metallate and in which the metal ester exists in residual orpartially reacted state with the cellulose, and then hydrolyzing thisintermediate by an aqueous medium treatment to regenerate the cellulosein essentially its original shape and appearance but possessing such newand improved properties as wool-like characteristics and crease, Wrinkleand mildew resistance.

In a more specific and preferred embodiment, the invention comprisessoaking a cellulosic textile material initially in an alkyl amine suchas ethylamine, removing excess amine therefrom and then soaking it in analkyl amine solution of an alkyl metal ester mixture such as ethyltitanate and ethyl antimonite, heating the resulting product toevaporate amine and by-product ethanol present, subjecting the resultingmaterial to heat treatment at from about 180 C. to complete themetallation reaction, and then regenerating the tendered intermediate byimmersion in aqueous media and recovering the improved product which canbe washed, dried, dyed, etc., and which possesses desired flameresistance, wrinkle resistance and wool-like properties.

In one practical adaptation of the invention a suitable textile or otherform of cellulosic material such as cotton, rayon, linen, ramie, etc.,is initially wetted, at room or elevated temperature, with asubstantially anhydrous organic amine swelling or complex agent, e.g.,ethyl amine, methyl amine, ethylene diamine, etc., and until desiredconditioning thereof is effected. Excess amine is then removed from thecomplexed amine cellulose product and the latter is then soaked in anorganic solution of an alkyl amine and an alkyl metal ester, such asethyl titanate, or a mixture of such titanate with an antimonite such asethyl antimonite. The resulting aminemetallate-cellulose composition isthen subjected to heating to substantially completely evaporate theamine, solvent and some by-product alcohol and to further react themetallate with the cellulose to form the tendered complex intermediate.This intermediate is then treated or immersed in water or other aqueousmedia to eifect regeneration of the tenderized cellulose intermediateand provide a product having substantially the macroscopic shape,tensile strength, washability, and high melting point of the originalfibrous cellulose material from which it is derived.

To a clearer understanding of the invention the following specificexamples are given. These are merely illustrative and are not to beconstrued as in limitation of the invention.

Example I A four-ounce per square yard cotton sheeting was titanated inthe following manner: 30 grams of the fabric was dried in an oven at C.and placed in a conventional type dyeing machine, comprising a closedjacketed vessel capable of temperature control and of flowing liquidsthrough the sample in either direction. 2300 cc. of anhydrous ethylaminecontaining about 0.1% of water was circulated through the fabric at 10C. for 30 minutes. 200 grams of tetra-n-butyl titanate Iwas then addedto the system and the circulation continued, while the temperature wasraised to 40 C. and a pressure of 2S p.s.i.g. prevailed in the system.This temperature condition was maintained for 30 minutes, after whichthe system was cooled and the solution drained away from the fabric.About 90 grams of the solution was held by the cloth. The drained clothwas then heated in the same vessel to C. for 1% hours to evaporate theresidual amine. Some n-butyl alcohol resulting from the titanationreaction between the butyl titanate and the cellulose was obtained withthe amine. The dried cotton at this point contained 0.4% of nitrogen and15% of TiO The titanated fabric was tenderized to about 50% of itsoriginal tensile strength, but on immersing in water, regenerated to itsoriginal strength and appearance.

Example I] I I An open weave cotton fabric weighing 2.6 ounces per yardwas titanated in the following manner in a resin reaction flask. 10grams of the dried fabric were immersed for two minutes at 16 C. in 400grams of ethylamine containing 125 grams of tetraethyl titanate. Thesolution was then drained from the cloth and the cloth allowed to standfor 30 minutes at temperatures just below the boiling point of theamine. During this aging, the material remained in the flask and wasprotected from atmospheric moisture. The flask Was then heated to 110 C.for 20 minutes to result in excess amine and by-product ethanol beingexpelled. The residual dry fabric was then soaked in water, washed anddried. The cloth product contained 10% TiO and had a crease recovery of60% as tested by the method described in Technical Bulletin #T-7,published December 1, 1947, by Monsanto Chemical Co., and in contrast tothe product obtained when recourse to solvent evaporation was noteffected, was free from visible dust.

Example III 10 grams of the fabric such as that used in Example II wastreated in a resin flask with 800 cc. of ethylamine for 30 minutes atreflux temperatures. After draining, 375 grams of ethylamine containing125 grams of tetraethyl titanate was added to the flask and the samplesoaked for one minute and then drained. The fabric retainedapproximately 20 grams of the solution. The cloth was then held belowthe boiling point of the amine for 30 minutes and was then heated to 110C. for 20 minutes to evaporate amine and ethanol present. The fabric wasthen steamed by blowing steam at 110 C. through the heated flask toresult in regeneration of the material to the original strong fabric.The washed and dried fabric was found to be dust-free and to contain17.7% TiO It had a crease recovery of 72% in accordance with the testingprocedure used in Example II.

Example IV Example III was repeated using a 15% by weight solution oftetraethyl titanate in dimethylamine. The product fabric contained 10%TiO was dust free, and had a crease recovery of about 60.

Example V A laboratory basket type centrifuge was modified to permitspraying of liquid into the basket and recirculation, duringcentrifuging, of a.- liquid treating agent through a fabric in thebasket. A sample of 2.6 ounce cotton fabric was placed peripherally inthe centrifuge basket. Ethylarninc at 10 C. was then passed through thefabric under centrifuging at 500 r.p.m. (radius 2 inches) for 30 minutesto effect preswelling. The amine was then drained from the reservoir anda solution, comprising 960 grams of ethylamine, 240 grams of tetraethyltitanate, and 5 grams of isopropyl antimonite, was passed through thecloth at C. for minutes during centrifuging. The circulation action wasthen stopped and the centrifuging speed increased to 2400 r.p.m. for 3minutes to remove the excess of liquid. The temperature of thecentrifuge enclosure was raised to 108 C. for minutes during slowrotation to effect evaporation and removal of the residual amine andby-product alcohols. A sample of the treated fabric was then removed,soaked in water, washed and dried. It 'Was found to contain 13% TiO 5%of Sb O was dust free, and exhibited a crease recovery rating of 65%.

Example VI A 56 gram skein of linen yarn of a 100/2 Lea count was driedat 105 C. for one hour and placed in a basket centrifuge vessel such asused in Example V. Ethylamine at 10 C. was circulated through thismaterial for minutes at 500 r.p.m. The amine was then drained off and asolution containing 1080 grams of ethylamine and 240 grams of tetraethyltitanate was introduced into the vessel and circulated through the skeinfor 15 minutes at 10 C. The reservoir was then drained and thecentrifuge rate increased to 2200 r.p.m. to throw out excess liquid. Theswollen titanated skein was then heated to 108 C. to remove residualamine and by-product alcohol and was then water regenerated as inExample IV. The resulting product was dust free, and contained 20% TiOand when woven into a plain, 6 ounce per yard fabric, had a creaseresistance value of 80.

Example VII A one gram swatch of 2.6 ounce cotton cloth was soaked inethylenediamine for 2 hours at room temperature while protected frommoisture. After draining briefly the amine swollen cloth was soaked at-90" C. for 30 minutes in 3 grams of tetraisopropyl titanate dissolvedin 33 grams of anhydrous ethylaminediamine. The solution was thendrained off and the amine evaporated from the fabric usin radiant heatat temperature of about 110-l20 C. After immersing the cloth in waterand washing and drying, it was found to contain 20% TiO and had a creaserecovery rating of 72.

Example VIII 10 grams of triethyl aluminate, Al(OEt) were dissolved ingrams of anhydrous ethylamine. A one gram swatch of 2.6 ounce cottoncloth was immersed in this solution for one hour in a reaction flask atreflux temperature. Excess liquid was then drained from the flask, thecloth being protected from atmospheric moisture by means of passage of acurrent of dry nitrogen thereover. The flow of nitrogen was continued toevaporate the amine leaving the aluminum compound in the fabric. Aftervaporization of the amine, the flask was warmed to about 108 C. in anoven with the nitrogen still flowing over the fabric to remove anyethanol resulting from the reaction between the cellulose and metallate.The cloth was then removed and immersed in water, washed and dried. Ithad an ash content of about 8% indicating the introduction ofconsiderable aluminum into the cloth. No dust appeared in the driedcloth. Its crease recovery rating was about 55.

Example IX A solution of n-butyl ferrate was prepared by reacting ferricchloride with n-butanol in the presence of ammonia. The reaction productwas mixed with an equal volume of benzene and the solid ammoniumchloride filtered oil. The benzene was distilled off leaving a solutionof butyl ferrate in butanol analyzing 28 grams of Fe per liter. Tengrams of this liquid was mixed with 100 grams of ethylenediamine. A onegram swatch of 2.6 02. cotton cloth was soaked for one hour at roomtemperature in pure ethylenediamine. It was then drained and immersed inthe butyl ferrate-amine mixture, warmed to 50 C. and held for one hourin a closed flask. The cloth was then removed and placed in a flaskthrough which a stream of dry air was passed. The air was preheated toabout 110 C. to hasten evaporation of the butanol and residual aminepresent. Steam at 110 C. was then passed through the hot flask for 5minutes, and was washed and dried. It had a reddish thrown color and onignition left a 5% ash residue. Its iron content was retained even afterrepeated launderings.

Example X Using the procedure of Example V a portion of the 2.6 ouncecotton fabric was first treated with ethylamine and then with a solutionconsisting primarily of 500 grams of tetraethyl titanate, 10 grams oftriisopropyl antimonite, 50 grams of triisopropyl aluminate and 2000grams of ethylamine. The washed, dried product fabric contained 10% TiO5% Sb O and 2.8% A1 0 It was flame resistant, substantially free ofafterglow, mildew resistant, resistant to loss of tensile strength onexposure to sunlight, and suffered substantially no yellowing on heatingto C. for 2 hours. The product of Example V, containingrio aluminum,yellowed markedly at this temperature.

Example XI 11 grams of 2.6 oz. cotton fabric was placed in thecentrifuge apparatus used in Example V. Ethylamine was circulatedthrough the sample for 30 minutes at C. and the sample drained at 50rpm. for 1 min. Using precautions against contacting the sample withatmospheric moisture, 1600 cc. of dry isopropanol and 425 g. oftetraisopropyl titanate were placed in the machine, warmed to refluxtemperature, circulated through the fabric for 30 min. and drained at2000 rpm. for 3 min. The temperature of the vessel, still closed againstatmospheric moisture, was raised to 108 C. in 40 min. and held attemperature for 20 min. The resulting dry, rather brittle tender fabricwas immersed in water and a strong fabric resulted containingapproximately 20% TiO and showed a crease recovery rating of about 75The significance of the crease recovery figures for the products of theabove examples, will be apparent from the following control figures:

Untreated Untreated Cotton Linen Wool Cloth Cloth CR=40 CR=30 CR=85Although described as applied to certain specific and preferredembodiments the invention is obviously not restricted to suchembodiments. Hence, many variations can he undertaken without departingfrom the underlying principles and scope of the invention.

Thus, in the first step of swelling a cellulosic material with theamine, the cellulose can be immersed in the pure amine or in thesolution of the amine in a suitable organic solvent (alcohol, benzene,toluene, xylene, etc.). The material can then be drained and immersed inthe amine solution of the alkyl metallate which may also contain avolatile organic solvent. After these swelling and treating steps theamine together with any volatile solvent present is evaporated from thecloth and in the presence of the alkyl metallate. The product at thispoint comprises an anhydrous metallated cellulosic intermediate adaptedto be recovered as a special intermediate product or treated with anaqueous medium to hydrolyze and stabilize the metall-ated cellulosicmaterial to final form. In using ancillary volatile organic solvents itis preferable that the organic solvent be more volatile than the amineused, but this is not essential. For simplification of operatingprocedures organic solvents use is preferably omitted, the cellulosematerial being swollen in the pure amine and then treated with the aminesolution of the alkyl metallate. If desired, the metallation process canbe effected as a onestep operation by immersing the original driedcellulosic material in a solution of the metal ester in the amine.

Amines useful as swelling agents herein comprise any primary orsecondary alkyl or aryl amine or mixtures thereof, more volatile thanthe alkyl metallates employed, and which, preferably, boil at notgreater than 180 C. Examples thereof include methylamine, ethylamine,propylamine, isopropy-lamine, dimethylamine, diethylamine,dimethylethylamine, diisopropylamine, methylethylamine, .butylamine,ethylenediamine, propylenediamine, morpholine, and the like. The degreeof metallation appears promoted to the maximum ranges by the use of thelower molecular weight, preferably straight chain primary alkyl amines.In some instances, a combination of a small primary amine molecule suchas methylamine, ethylamine or ethylenediamine can be used with a morebulky molecule such as isobutylamine, tetraiarybutylamine, diethylamine,diisopropylamine or morpholine, etc. While preferably the process iscarried out without the use of solvents other than the amines, morevolatile solvents such as cyclohexane, isopropyl alcohol, heptane andthe like can be used in conjunction therewith. However, it will be foundpreferable that they be removed as by draining or evaporation, prior toundertaking the final critical step of evaporating the amine from thecellulosic material in the presence of the alkyl metallate.

Metal esters utilizable herein comprise compounds, especially alkylmetallates, corresponding to the formula Me(OR) wherein Me includestitanium, zicronium, hafnium, thorium, aluminum, iron (ferric), e.g.,metals which form water insoluble oxides and have a coordination numberat least one greater than the valence of the metal in the oxide form(which number is usually 6), with R being a monovalent hydrocarbon orchlorinated hydrocarbon radical such as an alkyl (methyl, ethyl, butyl,amyl, isopropyl, isobutyl, isoamyl, beta-chloroethyl, etc.), cycloalkyl(cyclobutane, cyclopropyl, cyclopentane, cyclohexane, etc.), aryl(phenyl, benzyl, naphthyl, etc.), alkaryl (tolyl, xylyl, ethyl phenyl,etc.), aralkyl (benzyl, phenylethyl, phenylpropyl, etc.), and x is 3 and4, the valence of the metal in its highest state of oxidation. Alsoutilizable are the hydrolyzable esters of antimony, such as the variousantimonates and antimonites. They correspond to the formula (RO) S b,wherein R is a monovalent hydrocarbon radical, such as the variousalkyls, aryls, aralkyls, cycloalkyls mentioned above, e.g., methyl,ethyl, propyl, butyl, cyclopropyl, phenyl, naphthyl, tolyl, anthranyl,benzyl, xylyl, ethyl phenyl, phenyl propyl, etc., as well as themonochloro and dichloro derivatives of these compounds. Especiallyuseful are trialkyl antimonites in which the hydrocarbon radicalcontains from 1-12 and preferably from 1-6 canbon atoms. Examplesthereof include trimethyl, ethyl, isopropyl, .butyl, hexyl, octyl,benzyl, phenyl antimonites andtheir various mixtures. These esters areapplied under substantially anhydrous conditions, although the presenceof small amounts of water, as indicated in connection with the titaniumesters, can be tolerated. The antimony ester is preferably used incombination, that is, simultaneously with the titanium or zirconiumesters, or they may be applied sequentially, e.g., before or after thetitanating step, but prior to the water-washing step. Especially usefulare metal ester compounds containing an alkyl hydrocarbon radical of analcohol having from, say, 1-12 and preferably from 1-6 carbon atoms inits chain. In addition to the simple ortho esters of the metals whichare preferred for use, the partially hydrolyzed or condensedpolyrnetallates can be used, particularly those having a degree ofpolymerization not greater than 10. The alkyl metallates can be usedeither alone or in admixture with each other and the metallates of thegroup IVA metals, e.g., titanium, zirconium, hafnium, thorium, incombination with an alkyl antimonite are especially useful whenproduction of a product resistant to photodegradation is desired. Anespecially useful combination comprises an alkyl .titanate and an alkylantimonite. When such preferred combination is used from about 15-25% ofthe combined oxides of the metals is introduced into the cellulose.Preferably, the weight ratio of titanium oxide to antimony issubstantially equal. Useful ranges for the other contemplated metalscomprise the molecular equivalent ranges. In general, the final productcan contain from about 2% up to 40% or more of the metal or mixtures,calculated as the oxide, and usually contains from about 5-35 of metaloxide or oxides and preferably from about 10-30%. Specific examples ofalkyl metallates utilizable herein include tetraethyl titanate,hexaethyl dititanate, tetrapropyl titanate, tetraisopropyl titanate,octapropyl trititanate, tetramethyl titanate, tetraoctyl titanate,triethyl aluminate, triisopropyl aluminate, tributyl alumina-te,triethyl ferrate, triisopropyl ferrate, tetrapropyl zirconate,tetraethyl zirconate, tetrapropyl zirconate, and the like, including thevarious polyaluminates, polyferrates, and polyzirconates having D.P.s upto 10 and containing organic radicals of from one to 8 carbon atoms. Theester can be used with the amine either as a pure 7 liquid or as asolution of in an organic solvent (alcohol, benzene, toluene, xylene,cyclohexane, etc.).

The important step of evaporating in accordance with this invention theamine from the metallate Wetted cellulose advantageously effects animproved penetration and complete reaction of the metallating agent.This is evident from the lack of production herein of an undesired dustyform of product. Advantageously also, recourse to this step eliminatesthe necessity of resorting to an expensive organic solvent washingtreatment before the regeneration step and recovery of unreacted metalesters which induces dustiness. In carrying out the evaporation step theamine is evaporated from the cellulose while the later is in intimateassociation with the metallate and preferably only the amount retainedby the cellulosic material after the amine-metallate compositiontreatment is allowed to drain off. The amount of metal penetrating andremaining in the cellulosic material depends somewhat upon theconcentration of the solution with which the cloth is treated. It alsodepends upon the characteristics of the fabric with respect to theamount of liquid it can hold. With a relatively high concentration and ahigh liquid holdup one obtains on evaporation the higher amounts ofmetal oxide firmly aflixed in the product. When the amount of metaltake-up is small, either due to low concentrations of the treatingsolution or to low-holdup in the cloth, recourse can be had, if desired,to several treatments in succession. In such successive treatments, itis preferable that the process be carried through the step ofevaporating the amine and then the swelling and alkyl metallatetreatment is repeated. It is also possible to make successive treatmentsby carrying each through the hydrolysis step.

The use of a fluid aqueous medium for the hydrolysis step is alsovariable. Simple immersion in water is satisfactory. However, bysteaming the material, especially in the case of textile fabrics, theadvantage of removing small traces of volatile residues, especially theamines, is realized. Similarly, the cellulosic material can be immersedfor preswelling in the pure volatile liquid amine composition afterwhich it can be immersed in a liquid medium containing both the alkylmetallate and amine. If desired preswelling operation can be carried outin a solution of the amine in a suitable organic solvent after which theexcess is drained away and the metallation step carried out aspreviously described. Preferably, the swelling and metallating solutionsare substantially anhydrous. However, it is feasible that small amountsof water can be present in the amine solution employed in thepreswelling operation inasmuch as it becomes drained away prior to themetallation step. Alternatively, the amine swollen and metal complexedcellulose can be regenerated by contact with a fluid aqueous medium suchas water, steam or water vapor in a gaseous carrier. When combiningalkyl metallates of aluminum and titanium together with an alkylantimonite, it will be found advantageous to place the esters in oneamine solution. However, recourse to successive treatments andevaporation steps for each agent can be effected should this be desired.

The process is admirably suited to the treatment of long or continuouslengths of cotton textile materials. The fabric may be fed from a rollinto a range which consists for example of an initial chamber in whichthe fabric is immersed in a pure amine. The time of holding the cloth inthis liquid may be increased considerably by employment of the J box,well known in the textile industry. The next unit of the range would bea second chamber similar to the first and carrying a J box in which thema terial is penetrated with an amine solution of the alkyl metallate.Upon leaving this chamber, the excess solution can be pressed out aswith rollers and the liquid bearing cloth can be subjected totemperatures up to 180 C. to cause evaporation of the amines andby-product alcohols. The fabric can then pass to a final chamber in 8which the steam atmosphere of approximately 110 C. is maintained.Following this the material can be washed and dried by normalprocedures.

The manner in which the alkyl metallates affect the cellulosic materialsis not well known. It has been observed that this metallation tends toincrease resistance to inflammability and to improve crease recovery offabrics and to prevent mildew. It is thought that the metal compoundreacts and becomes chemically bonded to the cellulose to effect theseresults. It is possible that some crosslinking mechanism. will serve toexplain the new wool-like properties obtained. Combinations of variousreagents have certain effects. While titanium and zirconium seem bestfor flame retardance and crease recovery there is a considerableafterglow present when a titanated material has been ignited and theflame expired. Additional aluminum treatment reduces this afterglow. Theantimony serves to impart resistance to photodegradation of tensilestrength and dye color retention of titanated fabrics.

Various advantages of this treatment, namely, the introduction of flameresistance, crease recovery and resistance to mildew, into cellulosicmaterials has been known. The particular advantage of this inventionlies in a more economical and simple process which gives a use of theester remaining on the material under treatment and without causingundesirable dustiness in the final product. Another advantage resides inthe fact that when pure amines and metallates are used the physicalstrength of the anhydrous amine-metallate tenderized intermediate isconsiderably greater than when prepared in alcohol or hydrocarbonsolutions. This increase in strength of the in process material renderspossible the continuous range application described above. While thisprocess is particularly well adapted to the improvement of textilematerials, such as cotton, linen, ramie, and the like, it can also beapplied to other forms of cellulosic, such as wood pulp, wood, paper,cellulose sponges, cellulosic Wall board and insulating materials, etc.

While elevated or boiling temperatures can be used in the reaction ofthe metal ester with the cellulose being treated, these are notessential. The reaction can be accomplished at lower temperaturesthrough the employment of longer contact time and may be considered tobe at the discretion of the operator. The temperature used in removal ofsolvents after completion of the reactions is likewise flexible and onecan employ any suitable vaporization conditions. The variable reactiontimes, temperature, pressure of the system when swelling and complexingas well as when reacting and tenderizing the swollen and complexedproduct by ester treatment, are dependent upon the character of theinitial cellulose material, the physical attributes of the swellingagent and the degree of subsequent metallization or degree of change ofphysical and chemical properties desired. Hence, such conditions cannotbe specifically set out for all individual cases. Where relativelylow-boiling liquids are used, such as methylarnine, either lowtemperature operation at atmospheric pressure, or higher temperatureoperation at a pressure sufficient to maintain the major portion ofammonia derivative in the liquid state, is required. Short times ofcontact in both complexing steps, particularly at sub-zero temperatures,are advantageous and effective. A minimum of about 30 minutes of contactis preferred in the first step, that is, swelling and complexing thecellulose with the ammonia derivative; while a minimum of about 15minutes is preferred in the second complexing, or tenderizing step,during which addition and reaction is effected of the ester with thecomplexed cellulose. The reaction of theester-ammonia-derivative-complexed cellulose intermediate with waterdepends on penetration, a period of about 15 minutes to an hour at roomtemperature being preferred for use in this step.

As already stated, the invention provides a novel modified cellulosetextile having a novel combination of properties, including the singlefiber and fabric characteristics of wool, increased liveliness, greaterbulk, mildew resistance, crease and handle resistance, abrasionresistance, flame resistance, greater warmth and insulatingcharacteristics, washability and high melting point. Having the creaseresistance and resilience approaching that of wool, upon release afterpressing, the fibers and textile will readily spring apart, acharacteristic known as recovery. These attributes assure production ofa material having desired loft (high bulk or volume for a given weight)properties which afford ready production of wool-like, open, porousfabrics of high covering power and thick, warm fabrics with a minimum ofweight, qualities demanded in all apparel fabrics. Additionally, mymodified product exhibits other improved characteristics, e.g., mildewresistance, abrasion resistance, extensibility, elasticity and flameresistance, to afford a unique combination of properties which assureessential texture, warmth, fit, and durability characteristics andthereby enhance its value for acceptance by textile manufacturers andthe garment industry.

During the treatments, the strength of the cellulose material undergoingmodification becomes poor and fabrics such as used in the above exampleslose strength to such an extent that they are easily damaged bypunctures and tears. It is believed that the cellulose is degeneratedunder the conditions of the process by a breaking of the cross-linkageof cellulose. The titanium, or other metal, enters into combination withthe cellulose and the anhydrous product has poor strength due to thislack of cross linkage between molecular units of the cellulose fiber.Upon treatment with water, however, there is strong evidence thatcross-linkage again takes place and the fabric resumes its originalstrength. The cross-linkage at this time is believed to be somewhatdifferent and a new chemical bonding takes place through the titanium orother metal which has entered into the complex structure. The improvedproperties are believed to be due in large measure to this newcross-linkage or bonding both units of the cellulose structure. When theproduct has received normal washing, it is substantially nitrogen-freeindicating a relatively pure metal-modified cellulosic material.

Other evidence of the existence of a chemical combination of treatingmetal with the cellulose resides in the excellent mildew resistancewhich the metallated, especially the titanated, cellulose exhibits. Thisresult does not occur when recourse is had to precipitation of TiO in acellulosic fabric from an aqueous solution.

I claim:

1. A method for preparing a cellulose textile material possessingsubstantially the single fiber, liveliness, crease resistance and bulkcharacteristics of wool, comprising reacting a cellulose textilematerial under anhydrous conditions in the presence .of a volatile,liquid nitrogenous chemical swelling agent for cellulose selected fromthe group consisting of primary and secondary amine compounds whichswell the cellulose and form nitrogenous complexes with the celluloseand containing a radical selected from the group consisting of NH andNI-l, with a water hydrolyzable organic compound selected from thegrooup consisting of (1) an ester corresponding to the formula Me(OR)wherein Me is a metal selected from the group consisting of titanium,zirconium, hafnium, thorium, aluminum, iron and antimony, which forms awaterinsoluble oxide and has a valence selected from the groupconsisting of 3 and 4 and a coordination number the oxide state at leastone greater than the valence, R is selected from the group consisting ofhydrocarbon and chlorinated hydrocarbon radicals, and x corresponds tothe valence of the metal, and

(2) a condensed ester of said hydrolyZ-able ester resulting from thereaction of said ester with water, continuing said reaction until ahighly tendered metal ester-amine cellulose complex intermediate productis formed of substantially reduced tensile and tear strength over thatof the swollen cellulose textile obtained from said chemical swellingagent treatment, substantially completely evaporating said nitrogenouschemical swelling agent from said metal ester-amine cellulose complexintermediate product, contacting the resulting product with aqueousmedia consisting essentially of Water which regenerates and restoressaid product to substantially the tensile strength of the originaluntreated cellulose textile material, and recovering the resultingchemically modified cellulose product.

2. A method for preparing a cellulose textile material possessingsubstantially the single fiber, liveliness, crease resistance and bulkcharacteristics of wool comprising reacting a cellulose textile materialunder anhydrous con ditions in the presence of a volatile, liquid alkylamine chemical swelling agent for cellulose which swells the celluloseand forms nitrogenous complexes with cellulose, with a waterhydrolyzable organic antimony ester corresponding to the formula Sb(OR)in which R is selected from the group consisting of hydrocarbon andchlorinated hydrocarbon radicals, continuing said reaction until ahighly tenderized antimony ester-amine cellulose complex intermediate isobtained having a substantially reduced tensile and tear strengthcompared to the swollen cellulose textile obtained from said chemicalswelling agent treatment, substantially completely evapomating saidalkyl amine swelling agent from the said esterarnine cellulose complexintermediate, subjecting the resulting product to contact with aqueousmedia consisting essentially of water which generates and restores saidcellulose intermediate to substantially [the tensile strength of theoriginal untreated textile material, and recovering the resultingmodified product containing in chemical combination with cellulose fromabout 2% up to 40% of said metal, calculated as the oxide.

3. A method for preparing a cellulose textile material possessingsubstantially the single fiber, liveliness, crease resistance and bulkcharacteristics of wool comprising reacting a cellulose textile materialunder anhydrous conditions in the presence of a volatile, liquid alkylamine chemical swelling agent for cellulose which swells the celluloseand forms nitrogenous complexes with cellulose, with a waterhydrolyzable organic titanium ester corresponding to the formula'1"i(OR) in which R is selected from the group consisting of hydrocarbonand chlorinated hydrocarbon radicals, continuing said reaction until ahighly tenderized titanium ester-amine cellulose complex intermediate isobtained having a substantially reduced tensile and tear strengthcompared to the swollen cellulose textile obtained from said chemicalswelling agent treatment, substantially completely evaporating saidalkyl amine swelling agent from the said ester-amine cellulose complexintermediate, subjecting the resulting product to contact with aqueousmedia consisting essentially of water which regenerates and restoressaid cellulose intermediate to substantially the tensile strength of theoriginal untreated textile material, and recovering the resultingmodified product containing in chemical combination cellulose from about2% up to 40% of said metal, calculated as the oxide.

4. A method for preparing a cellulose textile material possessingsubstantially the single fiber, liveliness, crease resistance and bulkcharacteristics of wood, comprising immersing a cellulose textilematerial under anhydrous conditions in a volatile, liquid alkyl aminechemical swelling agent for cellulose which forms nitrogenous complexeswith cellulose until a swollen nitrogenous complexed cellulose productis obtained, removing under anhydrous conditions excess amine reactantfrom the swollen cellulose product and reacting said product underanhydrous conditions in a solution of a water hydrolyzable organic estercorresponding to the formula Me(OR) wherein Me is a metal selected fromthe group consisting of titanium, zirconium, hafnium, thorium, aluminum,iron and antimony, which forms a water-insoluble oxide and has a valenceselected from the group consisting of 3 and 4 and a coordination numberin the oxide state at least one greater than the valence, R is an alkylradical, and it" corresponds to the valence of the metal, continuingsaid reaction until an anhydrous, highly tendered metal ester-aminecellulose complex intermediate results having a tensile and tearstrength substantially reduced over that of the amine-swollen cellulosetextile obtained from said alkyl amine swelling agent treatment,removing under anhydrous conditions excess ester reactant from saidtenderized complex intermediate and substantially completelyvolatilizing said alkyl amine swelling agent therefrom, immersing theresulting complex intermediate in aqueous media consisting essentiallyof water which regenerates and restores the intermediate tosubstantially the tensile strength of the original untreated cellulosetextile and recovering the resulting modified cellulose productcontaining, in chemical combination with the cellulose, from about 5% to35% of said metal, calculated as the oxide.

5. A method for preparing a cellulose textile material possessingsubstantially the single fiber, liveliness, crease resistance and bulkcharacteristics of wool, comprising immersing a cellulose textilematerial under anhydrous conditions in a volatile, liquid alkyl aminechemical swelling agent for cellulose which swells the cellulose andforms nitrogenous complexes with cellulose until a swollen nitrogenouscomplexed cellulose product is obtained, removing under anhydrousconditions excess amine reactant from said product and reacting thelatter at the boil under anhydrous conditions with a solution of waterhydrolyzable titanium tetraisopropylate until a highly tendered metalester-amine cellulose complex intermediate is obtained having a tensileand tear strength substantially reduced over that of the swollencellulose textile obtained from said alkyl amine treatment, removingunder anhydrous conditions excess unreacted titanate reactant from saidcellulose complex intermediate and substantially completely volatilizingsaid alkyl amine swelling agent therefrom, subjecting the resultingproduct to contact with water which regenerates and restores saidintermediate to substantially the tensile strength of the originaluntreated cellulose textile material, and thereafter recovering theresulting chemically modified cellulose product.

6. A method for preparing a cellulose textile material possessingsubstantially the single fiber, liveliness, crease resistance and bulk.characteristics of wool, comprising immersing a cellulose textilematerial under anhydrous conditions in a volatile, liquid alkyl aminechemical swelling agent for cellulose which swells the cellulose andforms nitrogenous complexes with cellulose until a swollen nitrogenouscomplexed cellulose product is obtained, removing under anhydrousconditions excess amine reactant from said product and reacting theresulting product at the boil and under anhydrous conditions with asolution of alkyl ortho esters of antimony and titanium until a highlytenderized metal ester-amine cellulose complex intermediate is obtainedhaving a tensile and tear strength substantially reduced over that ofthe swollen cellulose textile obtained from said alkyl amine treatment,substantially completely evaporating the alkyl amine swelling agent fromsaid cellulose complex intermediate, subjecting the resulting product tocontact with water which regenerates and restores said intermediate tosubstantially the tensile strength of the original untreated cellulosetextile material, and thereafter recovering the resulting chemicallymodified cellulose product.

7. A method for preparing a cellulose textile material possessingsubstantially the single fiber, liveliness, crease resistance and bulkcharacteristics of wool, comprising immersing a cellulose textilematerial under anhydrous conditions in a volatile liquid alkyl aminechemical swelling agent for cellulose which swells the cellulose andforms nitrogenous complexes with cellulose until a swollen nitrogenouscomplexed cellulose product is obtained, removing under anhydrousconditions excess amine reactant from said product and reacting theresulting product at the boil under anhydrous conditions with a solutionof Water hydrolyzable tetraisopropyl antimonite and tetraisopropyltitanate until a highly tendered metal esteramine cellulose complexintermediate is obtained having a tensile and tear strengthsubstantially reduced over that of the swollen cellulose textileobtained from said alkyl amine treatment, removing under anhydrousconditions excess unreacted antimonite and titanate from said cellulosecomplex intermediate and heating the product to substantially completelyvolatilize and remove said alkyl amine swelling agent, subjecting theresulting product to contact with water which regenerates and restoressaid intermediate to substantially the tensile strength of the originaluntreated cellulose textile material, and thereafter recovering theresulting chemically modified cellulose product.

8. A method for preparing a cellulose textile material possessingsubstantially the single fiber, liveliness, crease resistance and bulkcharacteristics of wool, comprising immersing a cellulose textilematerial under anhydrous conditions in a volatile, liquid alkyl aminechemical swelling agent for cellulose which swells the cellulose andforms nitrogenous complexes with cellulose until a swollen nitrogenouscomplexed cellulose product is obtained, removing under anhydrousconditions excess amine reactant from said product and reacting theresulting product at the boil under anhydrous conditions with a solutionof ethyl ortho titanate and ethyl ortho antimonite until a highlytendered metal ester-amine cellulose complex intermediate is obtainedhaving a tensile and tear strength substantially reduced over that ofthe swollen cellulose textile obtained from said amine swelling agenttreatment, removing under anhydrous conditions excess unreacted titanateand antimonite reactants from said cellulose complex intermediate andheating the resulting product to evaporate and substantially completelyremove alkyl amine swelling agent remaining therein, subjecting theresulting product to contact with water which regenerates and restoressaid intermediate to substantially the tensile strength of the originaluntreated cellulose textile material, and thereafter recovering theresulting chemically modified cellulose product.

References Cited in the file of this patent UNITED STATES PATENTS2,009,015 Powers July 23, 1935 2,525,049 Signaigo Oct. 10, 19502,980,489 Gulledge Apr. 18, 1961 2,980,490 Gulledge Apr. 18, 1961FOREIGN PATENTS 517,464 Great Britain Jan. 31, 1940 OTHER REFERENCESSpeer: Industrial and Engineering Chem., February 1950, pp. 251455.

Gulledge: Industrial and Engineering Chem, March 1950, pp. 440444.

Moncriefi: Textile Colourist & Finisher, August 1950, pp. 394 and 395.

Loeb: Textile Research Journal, July 1954, pp. 654- 658.

Balthis: Abstract of Application S.N. 692,385, pub. May 16, 1950, 6340.6. 985.

1. A METHOD FOR PREPARAING A CELLULOSE TEXTILE MATERIAL POSSESSINGSUBSTANTIALLY THE SINGLE FIBER, LIVELINESS, CREASE RESISTANCE AND BULKCHARACTERISTICS OF WOOL, COMPRISING REACTING A CELLULOSE TEXTILEMATERIAL UNDER ANHYDROUS CONDITIONS IN THE PRESENCE OF A VOLATILE,LIQUID NITROGENOUS CHEMICAL SWELLING AGENT FOR CELLULOSE SELECTED FROMTHE GROUP CONSISTING OF PRIMARY AND SECONDARY AMINE COMPOUNDS WHICHSWELL THE CELLULOSE AND FORM NITROGENOUS COMPLEXES WITH THE CELLULOSEAND CONTAINING A RADICAL SELECTED FROM THE GROUP CONSISTING OF -NH2AND >NH, WITH A WATER HYDROLYZABLE ORGANIC COMPOUND SELECTED FROM THEGROUP CONSISTING OF (1) AN ESTER CORRESPONDING TO THE FORMULA ME(OR)XWHEREIN ME IS A METAL SELECTED FROM THE GROUP CONSISTING OF TITANIUM,ZIRCONIUM, HAFNIUM, THORIUM, ALUMINUM, IRON AND ANTIMONY, WHICH FORMS AWATERINSOLUBLE OXIDE AND HAS A VALENCE SELECTED FROM THE GROUPCONSISTING OF 3 AND 4 AND A COORDINATION NUMBER IN THE OXIDE STATE ONEGREATER THAN THE VALENCE, R IS SELECTED FROM THE GROUP CONSISTING OFHYDSROCARBON AND CHLORINATAED HYDROCARABON RADICALS, AND X CORRESPONDSTO THE VALENCE OF THE METAL, AND (2) A CONDENSED ESTER OF SAIDHYDROLYZABLE ESTER RESULTING FROM THE REACTION OF SAID ESTER WITH WATER,CONTINUING SAID REACTION UNTIL A HIGHLY TENDERED METAL ESTER-AMINECELLULOSE COMPLEX INTERMEDIATE PRODUCT IS FORMED OF SUBSTANTIALLYREDUCED TENSILE AND TEAR STRENGTH OVER THAT OF THE SWOLLEN CELLULOSETEXTILE OBTAINED FROM THE CHEMICAL SWELLING AGENT TREATMENT,SUBSTANTIALLY COMPLETELY EVAPORATING SAID NITROGENOUS CHEMICAL SWELLINGAGENT OM SAID METAL ESTER-AMINE CELLULOSE COMPLEX INTERMEDIATE PRODUCT,CONTACTING THE RESULTING PRODUCT WITH REGENGERATES CONSISTINGESSENTIALLY OF WATER WHICH REGENERATES AND RESTORES SAID PRODUCT TOSUBSTANTIALLY THE TENSILE STRENGTH OF THE ORGINAL UNTREATED CELLULOSETEXTILE MATERIAL, AND RECOVERING THE RESULTING CHEMICALLY MODIFIEDCELLULOSE PRODUCT.